Generally, refrigerated container systems facilitate transporting cargo in a cooled state to maintain a particular desired quality while the cargo is transported to intended destinations. The cargo is transported, stored, or otherwise supported within a cargo space of the transport container, and is maintained at a desired temperature within the cargo space using a transport refrigeration system.
A control unit typically provides automated monitoring and control of the status and operation of a refrigerated container system. For example, the control unit regulates the temperature of a cargo space within the container by turning a refrigeration unit on/off based on sensed temperature and a setpoint temperature. The control unit is also capable of sensing other conditions relating to the cargo space of the refrigerated container system. One such condition is the open/closed state of one or more doors provided on the refrigerated container for accessing the cargo.
The desirability of having a network of sensors in a refrigerated container system, both temperature and door state, is clear. However, incorporating wireless door sensors into control networks for refrigerated containers presents unique challenges that are described and addressed herein.